This information is provided free of charge by the Department of Industrial Relations
from its web site at www.dir.ca.gov. These regulations are for the
convenience of the user and no representation or warranty is made that the information
is current or accurate. See full disclaimer at http://www.dir.ca.gov/od_pub/disclaimer.html.

Subchapter 4. Construction Safety Orders
Article 20. Temporary Floors

§1635. Floors, Walls and Structural Steel Framed Buildings.

(a) For multifloor buildings, other than structural steel framed buildings, the
following shall apply:

(1) Every building shall have the joists, beams, or girders of floors below
the floor or level where any work is being done, or about to be done, covered
with flooring laid close together, or with other suitable material to protect
workers engaged in such building from falling through joists or girders, and
from falling substances, whereby life or safety is endangered.

(2) Every building which is of reinforced concrete construction, with reinforced
concrete floors, shall have the floor filled in, either with forms or concrete,
on each floor before the commencement of work upon the walls of the second floor
above or the commencement of work upon the floor of the next floor above.

(3) Every building having wooden floors other than a steel frame building shall
have the underflooring, if double flooring is to be used, laid on each floor
within the time prescribed above for reinforced concrete floors. Where single
wooden floors are to be used, each floor shall be planked over within the time
prescribed above for reinforced concrete floors.

(4) If a span of a floor on a building exceeds 13 feet, an intermediate beam
shall be used to support the temporary flooring, but spans not to exceed 16
feet may be covered by three-inch planks without an intermediate beam. The intermediate
beam shall be of a sufficient strength to sustain a live load of 50 pounds per
square foot of the area supported.

(5) If building operations are suspended and the temporary flooring required
by this article is removed, the building shall be replanked upon the resumption
of work so that every worker at work has a covered floor not more than two stories
below.

(6) Planked floors on buildings shall be tightly laid together of proper thickness,
grade and span to carry the working load; such working load to be assumed as
at least 25 pounds per square foot.

(7) Fall protection shall be required in accordance with Article 24.

(8) No person shall proceed with any work assigned to or undertaken or require
or permit any other person to proceed with work assigned to or undertaken by
either, unless the planking or nets required by this article are in place.

(b) For multifloor structural steel framed buildings more than two stories
high, the following shall apply: These provisions shall apply to buildings erected
in tiers or stories and shall not apply to steel framed buildings having large
open spans or areas such as, mill buildings, gymnasiums, auditoriums, hangars,
arenas, or stadiums.

(1) The derrick or working floor of every building shall be solidly decked
over its entire surface except for access openings.

(2) There shall be a tight and substantial temporary floor within two floors
below and directly under that portion of each tier of beams on which erection,
riveting, bolting, welding or painting is being done. For operations of short
duration of exposure to falling, fall protection shall be required as set forth
in Article 24 and Section 1710.

(3) Temporary floors shall be wood planking of proper thickness, grade and
span to carry the working load, but shall not be less than two inches thick,
full size undressed.

(4) Provision shall be made to secure temporary flooring against displacement
by strong winds or other forces.

(5) Planks shall extend a minimum of 12 inches beyond centerline of their supports
at each end.

(6) Wire mesh or plywood (exterior grade) shall be used to cover openings adjacent
to columns where planks or metal decking do not fit tightly. The materials used
must be of sufficient strength as required by Section 1632(b) to provide fall
protection for personnel and prevent objects from falling through.

(7) Metal decking where used in lieu of wood planking shall be of equivalent
strength and shall be laid tightly and secured to prevent movement.

(8) Floor planks or metal decking that are temporarily removed for any reason
whatsoever shall be replaced as soon as work requiring their removal is completed
or the open area shall be properly guarded.

(9) Prior to removal of temporary floor planks or metal decking, employees
shall be instructed by assigned supervision the steps to be taken to perform
the work safely and in proper sequence.

(10) When gathering and stacking temporary floor plank on a lower floor, in
preparation for transferring such plank for use on an upper working floor, the
steel erector's personnel shall remove such plank successively, working toward
the last panel of such floor, so that the work is always being done from the
planked floor.

(11) When gathering and stacking temporary floor planks from the last panel,
the steel erector's personnel assigned to such work shall be protected by a
personal fall protection system used in accordance with Article 24 and Section
1710.

(12) The sequence of erection, bolting temporary guying, riveting and welding
shall be such as to maintain the stability of the structural frame at all times
during construction. This applies to the dead weight of the structure, plus
weight and working reactions of all construction equipment placed thereon plus
any external forces that may be applied.

(13) Where a building is being constructed in sections, each section constitutes
a building.

(15) No person shall proceed with any work unless the planking and metal decking,
or nets required by this article are in place.

(c) Special Provisions Applicable to Floor Openings. Section 1632(b) applies
to floor openings at locations where steel erection work is taking place. This
subsection applies where work is in progress that requires floor openings to
be uncovered. For such work, all of the following requirements shall apply:

(1) The floor or working level where such work is in progress shall be under
the exclusive control of the steel erection employer and shall be barricaded
to prohibit entry by unauthorized personnel.

(2) The floor area adjacent to the floor opening shall be barricaded or the
floor opening shall be covered when not attended by steel erection personnel.

(3) All planking and other materials used to cover floor openings shall be
capable of safely supporting the greater of 400 pounds or twice the weight of
the employees, equipment and materials that may be imposed on any one square
foot area of the cover at any time. The cover shall have not less than 12 inches
of bearing on the surrounding structure.

(5) The placement of covers shall be verified by a qualified person prior to
each shift and following strong wind conditions.

(6) Workers shall be instructed and required to adhere to the following:

(A) Keep covers in place when not engaged in work requiring the opening to
be uncovered, and

(B) Never remove a cover by walking forward or by stepping into an area where
they cannot directly observe the surface their feet will touch.

(7) After work requiring floor openings to be uncovered has been completed
and prior to allowing other trades in the work area, the guarding and covers
for floor openings shall meet the provisions of Section 1632(b).